现在完成时的标志词是什么?答:放在否定句和一般疑问句句末。其他的标志词:just, before, recently,still, lately, never, ever, twice, on several occasions, in the past/last few days/weeks/months/years, (up to)these few days/weeks/months/years,this morning/week/month/year。3、before 表示之前发生的事情,放在句末...